All traffic destined to TCP port 80 is likely to be HTTP traffic and therefore is being marked with the packet mark http. Note, that the first rule has passthrough=yes while the second one has passthrough=no. (You can obtain additional information about mangle at )

All sub-queues have the main queue as the parent, thus the aggregate data rate could not exceed limits specified in the main queue. Note, that http queue has higher priority than other queues, meaning that HTTP downloads are prioritized.